- Problem 3 A Flagpole Has A Diameter D Of 30 Cm And Is 15 M Long 1 The Manufacturer Wants To Find The Bending Moment 1 (156.01 KiB) Viewed 31 times
Problem 3 A flagpole has a diameter (d) of 30 cm and is 15 m long (1). The manufacturer wants to find the bending moments (m) at the base of the pole for an air speed (V) of 100 km/hour with a density (p). To do so, a scale model of the flagpole is built with a diameter of 3 cm and a length of 1.5 m. (a) Find the dimensionless parameters and their functional relationship [Hint: to do the dimensional analysis about the bending moment, we also need to include the second moment of area (I) and Young's modulus (E) as the variables with the given parameters above. Use E, V, and d as the repeating parameters] (b) What must be the air speed at which the model is tested when the model has 1,000 times smaller bending moments than the prototype? (c) Now, we define a new model condition. We reduce the model air speed by 50 % and maintain the prototype velocity (100 km/hour). Other conditions such as the sizes of the prototype and model are maintained as same as before. Find the new moment ratio between the model and prototype: mm: mp, where the subscripts m and p represent the model and prototype. d m TH↓↓↓